ISSA Sports Nutrition & Exercise Performance

Question 1

During high-intensity exercise lasting less than 10 seconds, which energy system is primarily used?

Accepted Answer

Phosphocreatine (ATP-PCr) system

Answer

The ATP-PCr system provides immediate, anaerobic energy for maximal efforts lasting up to approximately 10 seconds by resynthesizing ATP from stored phosphocreatine.

Question 2

What is the recommended carbohydrate intake per hour for endurance athletes during exercise lasting longer than 90 minutes?

Accepted Answer

30–60 g/hr

Answer

Research supports consuming 30–60 g of carbohydrates per hour during prolonged endurance exercise to maintain blood glucose and spare muscle glycogen.

Question 3

Which type of muscle fiber is most reliant on aerobic metabolism and is highly resistant to fatigue?

Accepted Answer

Type I

Answer

Type I (slow-twitch) fibers have high mitochondrial density and capillary supply, making them primarily aerobic and highly fatigue-resistant.

Question 4

Carbohydrate loading (glycogen loading) is most beneficial for which type of athletic event?

Accepted Answer

Endurance events lasting more than 90 minutes

Answer

Carbohydrate loading maximizes muscle glycogen stores and benefits events where glycogen depletion limits performance—typically those lasting beyond 90 minutes.

Question 5

What is the primary role of branched-chain amino acids (BCAAs) during prolonged endurance exercise?

Accepted Answer

Serving as an energy substrate and potentially reducing central fatigue

Answer

BCAAs can be oxidized for energy during prolonged exercise and may reduce central fatigue by competing with tryptophan for transport across the blood-brain barrier, limiting serotonin production.

(ISSA) International Sports Sciences Association Certified Nutritionist Practice Test

(ISSA) International Sports Sciences Association Certified Nutritionist Practice Test

ISSA Sports Nutrition & Exercise Performance